A finite frequency seismic crosshole tomography based on thin layered model

Seismic crosshole tomography is a key method for getting velocity profile of crosshole. Algebra reconstructs is widely used in seismic crosshole tomography,including ART and SIRT, but the travel time and path must be computed on tomography by ray tracing.In order to obtain the shortest path within Fresnel zone,based on the Bube’s (2001) idea. we are constructed an unconstrained optimization function. add to penalty item involved ray length, that is related to the traveltimes of the path and realized ray tracing of finite frequency seismic wave, on thin bed layer model and realized the finite frequency seismic crosshole tomography.